The invention pertains generally to devices for conveyance of sewage from the holding tanks of recreational vehicles into sewer pipes at campgrounds, and more particularly to the manner of connection of the flexible hose conveying the sewage from the recreational vehicle, to the sewer pipe, and the manner of maintaining closure of the sewer pipe inlet when not in use.
The common manner of draining sewage from the holding tanks of a recreational vehicle is by attaching one end of a flexible hose to the outlet of the holding tank, and connecting the other end of the flexible hose to the inlet of a campground sewer pipe. See U.S. Pat. No. 4,180,102, Larkin, col 1, lines 12-14.
In campgrounds familiar to applicants the inlet of the campground sewer pipe commonly has a diameter of approximately 3 inches, which is also the diameter of the commonly used flexible hose. The commonly used procedure is to forcibly stuff the flexible hose into the inlet of the campground sewer pipe, which is difficult because they are of approximately the same diameter, the flexible hose outer diameter being slightly oversized for the inner diameter of sewer pipe.
During drainage of the holding tank the pressure of fluid in the flexible hose causes a back pressure which often pushes the end of the flexible hose out of the sewer pipe, causing a spillage of sewage, which creates an unsanitary and quite messy condition. Efforts are often made to hold the flexible hose in the sewer pipe by the use of rope, rocks and other crude methods, but none of these methods has been found satisfactory.
In the commonly used procedure the sewer pipe is closed off when not in use, by screwing a cap onto the inlet of the sewer pipe. However, in practice the cap is often left off, because the threads on the sewer pipe have become dirty or corroded, and the cap will not screw on; or because the cap has been lost.
The present invention solves both of the above-described problems by providing a single device of quite simple form, easily and inexpensively fabricated, which may be readily and quickly used both to securely attach the flexible hose to the inlet of the sewer pipe by means of a pin engaging both the flexible hose and holes in a base permanently attached to the sewer pipe, and may with equal facility also be used to close off the sewer pipe when not in use, by means of a stopper attached to the pin and flexibly but permanently attached to the base.
U.S. Pat. No. 4,133,347 to Mercer discloses a waste evacuation attachment for recreational vehicles, in which a cylinder 16, connected to the sewage outlet 10 of a recreational vehicle by means of an elbow-shaped mounting piece 18, contains an accordion hose 26. The hose 26 has at its outer end a sleeve 34, having pegs 36 for connection to hooks 38 on the outer end of the cylinder 16, and having an end cap 40. Col 2, lines 4-45; FIG. 2. To drain sewage from the recreational vehicle, hose 26 is extended from inside cylinder 16 and sleeve 34 (at the end of hose 26) is connected to a campground waste receptacle 54. Col 3, lines 13-15; FIG. 5. However, the patent, although indicating that sleeve 34 is connected to waste receptacle 54 (col 3, lines 13-15, 53-55; col 4, lines 43-45), is completely silent as to any structure which is used to effect this connection. Such structure is a principal focus of the present invention.
U.S. Pat. No. 4,180,102, Larkin, discloses a sewer connector for recreational vehicles, having a flexible hose 12 connected to the recreational vehicle by a connector 14, having at the outer end of the hose 12 a connector 20 for connection to a sewer ground line. Col 2, lines 12-27; FIG. 1. The only disclosure as to the manner of connecting connector 20 and hose 12 to the ground sewer line is the statement that connector 20 "may be simply an extension or a threaded device for connection to the ground sewer line." Col 2, lines 24-27.
Applicants' invention offers the advantage of not requiring the use of threads in a connection joining the flexible hose to the campground sewer pipe. Because applicants' invention does not require screw engagement of a threaded connection, the connection may be made more quickly with applicants' invention. Also, the use of a threaded connection has the disadvantage, that when one twists the flexible hose through several turns to engage the threaded connection, the twisted hose will apply a counter torque, thus tending to unscrew the connection.
The only other patents found in a pre-filing patentability search ordered by applicants are U.S. Pat. No. 3,323,818, Winchell; U.S. Pat. No. 4,274,455, Simons; and U.S. Pat. No. 3,934,904, Hord. None of these three patents contains disclosures specifically directed to recreational vehicles or to sewage disposal plumbing apparatus.
Winchell discloses a locking telescoping joint in which a cylinder tube 20 slides within a tubular member 10 having a rectangular cross section, which joint has a locking cam in the form of a pin 28 which extends through arcuate slots 24 and 26 in the cylinder 20 and engages the inner surface of the tubular member 10. The pin 28 lies on a diagonal of the square cross section of tubular member 10, when the joint is unlocked, and is free to slide longitudinally in this configuration. Col 2, lines 36-47; FIG. 1. The joint is locked by rotating tubes 10 and 20 with respect to one another, whereupon the arcuate slots 24 and 26 tilt the pin 28, also rotating the pin 28 about the axis of the tube 20, achieving a cam locking effect as the pin 28 is wedged against the sides of the square inner cross section of tube 10. Col 2, lines 48-70; FIGS. 1-2.
Applicants' invention involves a structure which is simpler and easier to operate and fabricate than that of Winchell. In applicants' invention the pin is merely inserted through two holes, not arcuate slots, and no twisting action is required to effect a cam lock wedging effect. In applicants' invention the flexible hose is secured to the base and thus to the sewer pipe by the pin which is simply inserted through the holes in the base, across the space between two folds of the flexible hose.
Winchell also discloses that previously, "slidable adjustable joints have involved interfitting sleeves which are fastened in adjusted position by bolts, set screws, pins fitted into aligned holes and other arrangements which are slow and difficult to operate . . ." Col 1, lines 18-21. Thus Winchell, though referring to the use of pins fitted into aligned holes, does not suggest that such a mechanism could afford part of a mechanism to quickly and easily secure the flexible hose to the campground sewer pipe, as in applicants' invention. If anything, Winchell suggests that such an approach would yield a mechanism which would be slow and difficult to operate.
Simons discloses a toner loading device for manually loading toner into a photocopy machine or computer printout machine. The apparatus has a flexible hose 16 at one end of which is a coupling 24 which may be closed by means of a cap 34, attached to coupling 24 by a chain. Col 3, lines 12-15; 35-37; FIG. 3.
Hord discloses an apparatus for connecting a hose to a drum, in which sleeves 20 and 30 are connected by set screws 36 which engage matching threaded apertures 32 and 34 in the sleeves 30 and 20 respectively. The structure is quite different in form from that of applicants' invention.
The patents known to applicants do not suggest the present invention, described in detail below.